package Bite;

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main2 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            StringBuilder stringBuilder = new StringBuilder(in.next());
            for (int i = 0; i < stringBuilder.length() - 1; i++) {
                if (stringBuilder.charAt(i) == stringBuilder.charAt(i+1)){
                    stringBuilder.delete(i,i+2);
                    i = -1;
                }
            }
            if (stringBuilder.length() == 0){
                System.out.println(0);
            }else {
                System.out.println(stringBuilder);
            }
        }
    }
}
